The final footnote to this book gives direction to the choir director who used this chapter as part of Israel's formal worship. Habakkuk specified the use of stringed instruments to accompany the singing undoubtedly because they set the proper mood.
The book opened with a dialogue between Habakkuk and Yahweh in which the prophet vented his fears and the Lord responded in love (ch. 1). Then it proceeded to a dirge in which the Lord explained the wickedness of the instrument that He would use to judge Judah, the Babylonians, and promised their ultimate destruction (ch. 2). It closes with a doxology in which Habakkuk praised God and recommitted himself to faith in and faithfulness to Yahweh as he anticipated hard times to come (ch. 3).
This book can be a great help to people who are discouraged about their present circumstances and or can see nothing good coming in the future. It helps us adjust our attitude from one of pessimism and even despair to optimism and rejoicing. The crucial issue is whether we will listen to God and believe Him, namely, exercise faith.